[Correction: 2 pm ET 10/6/11] The big bet at Cambridge, MA-based Tokai Pharmaceuticals is on prostate cancer, and now the size of that bet is getting a lot bigger.
Tokai is announcing today it has raised $23 million in a Series D3 financing, which included its existing investors Novartis Venture Fund, Apple Tree Partners, and angel investors. The company has also hired a new CEO, Martin Williams, who comes over from Watertown, MA-based Dicerna Pharmaceuticals, where he was chief business officer. Seth Harrison of Apple Tree, who had been the company's acting CEO, will remain as chairman of the board. Tokai has now raised a total of $57 million since its founding in 2004.
The new money will go toward Tokai's lone drug in development, galeterone (TOK-001), as it advances into the second of three phases of trials normally required for FDA approval. The drug, as I have previously described, targets prostate cancer cells that become resistant to standard hormone-deprivation therapies. Tokai's drug is supposed to hit three different molecular targets, which the company hopes will give it an advantage over a more narrowly targeted drug marketed by Johnson & Johnson and another in development from Takeda Pharmaceuticals and San Francisco-based Medivation. About 30,000 men in the U.S. die each year from prostate cancer, and the numbers are expected to increase as baby boomers get this common disease of aging.
"We think we have a potential blockbuster," Harrison says.
Prostate cancer is commonly treated with drugs that shut down production of testosterone hormones that are known to fuel the growth of tumors. Those treatments tend to work for years, although over time, tumors find a way to develop resistance. Tokai is zeroing in on blocking three of the ways tumors grow after they've become resistant to standard hormone blockers. The Tokai drug is designed to hit a receptor prostate cancer cells use for picking up trace amounts of testosterone left in the body. The drug is also designed to block an enzyme called CYP17 that allows the body to make small amounts of testosterone in adrenal glands. And the drug is also supposed to reduce the number of hormone receptors in prostate cancer tumors, essentially so they can't vacuum up any testosterone in the body.
Tokai isn't saying much yet about the evidence it has gathered to support this approach. The company has completed a Phase I clinical trial that enrolled 49 patients at a variety of doses to assess safety, says Jodie Morrison, Tokai's vice president of clinical affairs and acting chief operating officer. Tokai is waiting to discuss the data in detail at a future medical meeting. But Morrison did say that the drug showed an ability to lower PSA scores, a common prognostic marker for prostate cancer, and that it demonstrated some ability to shrink tumors according to standard criteria known as RECIST.
[Correction: An earlier version of this story said Takeda is partnered with Medivation. It should say Astellas.] Johnson & Johnson's abiraterone (Zytiga) recently won FDA approval, and Astellas Pharma/Medivation's MDV-3100 is further along in development than Tokai's drug. Still, Harrison says the company believes it can differentiate its drug on side effects—particularly one known as mineralcorticoid excess.
Tokai is still combing through the results from its Phase I study, which will determine what kind of trial design it selects for the next stage, Morrison says. But the trial will be an intermediate step, or a "very strong Phase II," as Morrison put it, on the way toward a pivotal study that determines the safey and effectiveness of the drug.